TABLE 3.

Subgroup analysis of STS between two groups

Frequency (Hz)	Ears	Mean difference (post − pre) hearing threshold dB HL
		Negative STS (improvement in hearing threshold)				Positive STS (increase in hearing threshold)
		Study		Control		Study		Control
		Mean	SD	Mean	SD	Mean	SD	Mean	SD
250	Right	−3.182	6.692	−1.833	6.086	6.087	6.208	6.512	5.725
	Left	−3.100	6.218	−2.568	5.965	1.400	5.686	5.875	6.969
500	Right	−2.727	5.678	−2.833	5.522	3.043	8.082	2.674	6.487
	Left	−2.900	5.722	−3.649	4.662	2.800	5.788	2.375	6.503
1000	Right	−2.727	5.166	−3.333	5.142	1.304	5.481	1.860	5.003
	Left	−3.300	6.195	−3.514	4.694	1.000	5.000	2.500	5.189
2000	Right	−3.273	6.102	−3.167	4.251	3.696	5.049	1.744	3.761
	Left	−2.900	5.258	−1.892	4.142	0.800	4.933	1.625	5.357
3000	Right	−5.545	5.906	−3.833	5.363	1.304	4.322	1.279	5.128
	Left	−3.600	5.349	−3.514	4.227	0.600	4.163	1.625	6.736
4000	Right	−3.273	6.471	−4.167	6.029	0.435	5.623	2.558	5.913
	Left	−2.800	4.861	−4.189	6.402	2.600	7.089	3.750	7.824
6000	Right	−5.000	7.071	−2.500	5.835	4.130	7.783	5.581	9.711
	Left	−2.700	7.299	−2.568	6.414	3.400	8.505	4.375	7.778
8000	Right	−4.000	6.625	−4.667	6.288	3.261	7.008	5.465	10.846
	Left	−3.200	6.606	−4.324	7.743	0.800	6.238	5.375	10.401

Note: In the negative STS results, the negative mean different hearing threshold of the study group showed the better results of improvement in hearing threshold than the control group without significance. Additionally, in the positive STS results, the positive mean different hearing threshold of the study group demonstrated the lower results of increase in hearing threshold than the control group at frequencies of 250 Hz, 3 KHz, 4 KHz, 6 KHz, and 8 KHz without significance. Independent Samples t Test.

Abbreviation: STS, significant threshold shift.